<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>
        *{
            margin: 0px;
            padding: 0px;
       }
        /* div#center{
            width: 1090px;
            height: 100px;
            background-color: green;
            margin: 0 auto; 
        } */
        header{
            width: 100%;
            height: 176px;
            background-color: red;
             /* position:fixed;
            top:0px; */
        }
        article{
            width: 100%;
            height: 800px;
            background-color: pink;
            /* margin-top: 176px;  */
        }
        div#center header div{
            height: 50px;
            border: 3px solid orange;
        }
        .header_nav{
            width: 100%;
            height: 50px;
            border: 3px solid blue;
            float: left;
            margin-top: 112px;
            position: sticky;
            top: 0px;
        }
        article{
            display: inline-block;
        }
        section{
            width: 110px;
            height: 364px;
            background-color: palegoldenrod;
            margin-left: 30px;
            margin-top: 30px;
            position: sticky;
            top:70px;
        } 
        /* div.center header div:last-child{
            position: sticky;
            top:0px;
        } */
    </style>
</head>
<body>
    <div id="outer">
        <div id="center">
            <div class="header_nav"></div>
            <header>
                <div></div>
                <div></div>
            </header>
            <article>
                <section></section>
            </article>
            <footer></footer>
        </div>
    </div>
</body>
</html>